1—Field of the Invention
This invention is related to elements employed in the petroleum industry in general but it particularly refers to a Free Mandrel System with protected casing. Its main specific purpose is to be applied to petroleum exploitation for the multiple selective injection of fluids, liquids or gases, in different formations of an injection well.
2—Description of Related Art
The present state of technology of mandrel systems for the injection of fluids in several formations only use fixed installations at the bottom hole. Consequently, when it is necessary to repair or replace any of the injection valves placed inside the mandrel, they have to be brought up to the surface. In order to perform this operation, the well has to be depressurized so injection has to be stopped; each of the injection valves have to be raised one at a time from the bottom hole to the surface. After the necessary repair or replacements are made, each of the injection valves have to be lowered again one at a time, and only after they are re-installed, production is resumed. All of the above mentioned operations require not only specialized equipment and personnel but also, down time, during which the well is not operating, and lead time, between order and arrival of the equipment at the well site to start with the operations.
The following documents are related to the present invention:
Document NumberDateNameClassificationAU.S. Pat. No. 4,671,352June 1987Magee Jr. et al166-334BU.S. Pat. No. 4,462,465July 1984Strickland166-334CU.S. 2004238218(A1)December 2004Runia. Douwe Johannes et al.E21B/60—DU.S. 2005011678(A1)January 2005Akinlade Monsuru Olatunji et al.E21B21/00—EU.S. Pat. No. 4,050,516(A)September 1977Canterbury Robert HoustonE21B34/06—FU.S. Pat. No. 4,433,728 (A)February 1984Sydansk Robert D et alC09K8/50—GU.S. Pat. No. 4,433,729 (A)February 1984Sydansk Robert DC09K8/50HRU2002126207 (A)February 2004Stedzhemejer Dzhordzh Leo et alE21B43/00